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What This Error Means

SHARP Error 21 typically indicates a problem with the main motor, its drive circuit, or an insufficient power supply to the printer.

Detailed Explanation

Error code 21 on a SHARP printer points to an issue with the main motor, which is responsible for driving various critical components like the scanning unit, paper feed, and fuser unit. This error often arises when the printer's internal diagnostics detect that the main motor is not operating at the correct speed, is drawing too much current, or is not responding at all. It could be a mechanical fault within the motor itself, such as worn gears or a seized bearing, preventing it from rotating freely. Beyond a mechanical failure, the error can also stem from the motor's control circuit board or an inadequate power supply. If the power coming into the printer is unstable or insufficient, the motor might not receive the necessary voltage or current to function correctly, triggering this error. Less commonly, a foreign object obstructing the motor's movement or a loose connection to the motor can also manifest as Error 21. It's a critical error because the main motor is fundamental to almost all printing operations.

DIY Troubleshooting Steps

Try these steps before calling a specialist

1
Perform a complete power cycle: Turn off the printer using the main power switch, unplug it from the wall outlet, wait for at least 5-10 minutes, then plug it back in directly to a wall outlet (avoiding surge protectors or power strips) and turn it on.
2
Check for any obvious obstructions: Open all accessible covers (paper trays, front cover, side covers) and carefully look for any jammed paper, foreign objects, or debris that might be impeding internal mechanisms.
3
Verify power supply: Ensure the printer is plugged directly into a functioning wall outlet. If it's on a power strip or UPS, try plugging it directly into the wall to rule out external power supply issues.
4
Inspect ventilation: Make sure the printer's ventilation ports are not blocked, as overheating can sometimes cause components to malfunction or shut down.
5
Reset the error: If the error persists after checking for obstructions and power cycling, try to clear the error message from the control panel if an option is available. Sometimes a simple reset can re-initialize the motor's status.
6
Listen for unusual sounds: Pay attention during startup or when the error occurs. Grinding, whirring, or clicking noises could indicate a mechanical issue with the motor or gears.

When to Call a Specialist

You should call a specialist if, after performing all the DIY troubleshooting steps, the Error 21 persists. This error often points to a component-level failure, such as a faulty main motor, a damaged motor drive board, or a more complex power supply unit issue. These repairs typically require specialized tools, diagnostic equipment, and technical expertise to safely replace internal components and verify proper operation. Attempting to disassemble the printer further without proper training can lead to additional damage or personal injury.

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SHARP Error Code 21